Characterization of mammalian sedoheptulokinase and mechanism of formation of erythritol in sedoheptulokinase defficiency
Characterization of mammalian sedoheptulokinase and mechanism of formation of erythritol in sedoheptulokinase defficiency
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DOI：
10.1016/j.febslet.2008.08.024
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发表时间：
2008-10-15
期刊：
影响因子：
3.5
通讯作者：
Van Schaftingen, Emile
中科院分区：
文献类型：
--
作者：
Kardon, Tamas;Stroobant, Vincent;Van Schaftingen, Emile
我们的目的是鉴定SEDOGULK形成的产物，并了解SEDOGULK缺乏症患者赤藓糖醇的形成机制。小鼠重组七糖激酶对七糖具有明显的特异性，其反应产物为7-磷酸七糖。植物提取物中七碳七糖的分析表明，这种糖存在于胡萝卜(约7 MU/g)和几种水果中。蔗糖1-磷酸被证明是醛缩酶B的底物，它将其裂解为二羟基丙酮-磷酸和红素。这表明，在缺乏七糖-7-激酶的患者中，七糖被果糖激酶磷酸化为七糖1-磷酸。后者被醛缩酶B切割后会形成红血球，然后红血球就会被还原成赤藓糖醇。(C)2008年，由Elsevier B.V.代表欧洲生化学会联合会出版。
Our aim was to identify the product formed by sedoheptulokinase and to understand the mechanism of formation of erythritol in patients with sedoheptulokinase defficiency. Mouse recombinant sedoheptulokinase was found to be virtually specific for sedoheptulose and its reaction product was identified as sedoheptulose 7-phosphate. Assays of sedoheptulose in plant extracts disclosed that this sugar is present in carrots (approximate to 7 mu nmol/ g) and in several fruits. Sedoheptulose 1-phosphate is shown to be a substrate for aldolase B, which cleaves it to dihydroxyacetone-phosphate and erythrose. This suggests that, in patients defficient in sedoheptulose-7-kinase, sedoheptulose is phosphorylated by fructokinase to sedoheptulose 1-phosphate. Cleavage of the latter by aldolase B would lead to the formation of erythrose, which would then be reduced to erythritol. (C) 2008 Published by Elsevier B. V. on behalf of the Federation of European Biochemical Societies.